Crystal structure, Hirshfeld surface and frontier mol-ecular orbital analysis of 9-(3-bromo-4-hy-droxy-5-meth-oxy-phen-yl)-3,3,6,6-tetra-methyl-3,4,5,6,7,9-hexa-hydro-1-xanthene-1,8(2)-dione.

In the fused ring system of the title compound, CHBrO, the mean plane and maximum deviations of the central pyran ring are 0.0384 (2) and 0.0733 (2) Å, respectively. The cyclo-hexenone rings both adopt envelope conformations with the tetra-substituted C atoms as flap atoms, whereas the central pyran ring adopts a flattened boat conformation. The central pyran and phenyl substituent rings are almost perpendicular to each other, making a dihedral angle of 89.71 (2)°. In the crystal, pairs of mol-ecules are linked O-H⋯O hydrogen bonds, forming inversion dimers with an (20) ring motif. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (50.6%), O⋯H/H⋯O (22.9%) and C⋯H/H⋯C (11.1%) contacts. Quantum chemical calculations for the frontier mol-ecular orbitals were undertaken to determine the chemical reactivity of the title compound.